Various, partially opposite demands are made on housings for exhaust-gas treatment units such as mufflers, catalyst or particulate filters. The demands relating to a high rigidity, acoustics, and appearance of the housing are in contrast to the demands relating to a weight that is as low as possible. Usually, such housings are therefore produced from a thin metal sheet which is provided with ribs or beads. The desired rigidity, acoustics, and appearance of the housing are thus obtained with a low amount of material used. The manufacture of such beaded housings is however complex and cost-intensive since they are usually manufactured in a monocoque design.
The object of the invention is to provide a method of manufacturing a housing of an exhaust-gas treatment unit which is both cost-efficient and provides a lightweight housing having the required rigidity.